Tocilizumab (Actemra®) is a recombinant humanized monoclonal IgG1 antibody that binds to and inhibits the biologic activity of the interleukin-6 receptor (IL-6R) in in vitro and in vivo assay systems. Tocilizumab contains human framework regions and the complementarity-determining regions of a murine antibody that binds to IL-6R. Tocilizumab has an approximate molecular weight of 148 kD.
Tocilizumab is presently indicated for the treatment of (i) rheumatoid arthritis (RA): alone or in combination with methotrexate or one or more Disease-Modifying Anti-Rheumatic Drugs (DMARDs) in adult patients with moderately to severely active RA who have had an inadequate response to one or more DMARD (ii) polyarticular juvenile idiopathic arthritis (PJIA): alone or in combination with methotrexate in patients two years of age and older with active PJIA; and (iii) systemic juvenile idiopathic arthritis (SJIA): alone or in combination with methotrexate in patients two years of age and older with active SJIA (from Actemra® Prescribing Information dated Oct. 21, 2013, Genentech, Inc.).
For intravenous (IV) infusion Tocilizumab is supplied as a sterile, preservative-free solution with a pH of about 6.5 and a Tocilizumab concentration of 20 mg per mL. Single-use vials containing 80 mg per 4 mL, 200 mg per 10 mL, or 400 mg per 20 mL of tocilizumab are available for IV administration. Injectable solutions of tocilizumab are formulated in an aqueous solution containing disodium phosphate dodecahydrate and sodium dihydrogen phosphate dehydrate (as a 15 mmol per L phosphate buffer), polysorbate 80 (0.5 mg per mL), and sucrose (50 mg per mL). (from Actemra® Prescribing Information dated Oct. 21, 2013, Genentech, Inc.).
For subcutaneous administration tocilizumab is supplied as a sterile, colorless to yellowish, preservative-free liquid solution with an approximate pH 6.0. Tocilizumab is supplied as a 1 mL ready-to-use, single-use prefilled syringe (PFS) with a needle safety device. Each device delivers 0.9 mL (162 mg) of Tocilizumab, in a histidine buffered solution composed of tocilizumab (180 mg/mL), polysorbate 80, L-histidine and L-histidine monohydrochloride, L-arginine and L-arginine hydrochloride, L-methionine, and water for injection. (from Actemra® Prescribing Information dated Oct. 21, 2013, Genentech, Inc.).